Coded input and output apparatus for typewriters

ABSTRACT

A typewriter is provided with an input and output apparatus having receiving and transmitting bars. The receiving bars are urged by springs and are latched to latches controlled by electromagnets. A series of decoding levers senses the receiving bars on receiving of input signals for setting one of said decoding levers corresponding to the combination of positions of the receiving bars. A lever rocked by a continuously rotating cam causes the decoding lever so set to be shifted for actuating the type-hammer associated thereto.

States atent 1 retti et al.

comm INPUT AND ourrur APPARATUS ron rvrnwnrrsns Inventors: Franco Bretti, Are di Caluso (Turin); Franco Valle, Ivera ITurin). both of Italy Assignee:

Italy Filed: July 19, 1972 Appl. No.: 273,080

Foreign Application Priority Data July 20, i971 Italy 69435/71 U.S. Cl. 197/19, 197/17 Int. Cl B4lj 5/30 Field of Search 197/16, 17, 19, 20, 98

References Cited UNITED STATES PATENTS Blodgett 197/19 Blodgett 197/20 Ing. C. Olivetti & C., Turin.-

[ Sept. 24, 1974 2,895,337 7/]959 Moring et ul. l97/l7 UX 3,306,417 2/l9o7 (inssino cl nl. l97/l7 3,327,828 6/]967 Dunnatl l97/l6 X 3,342,296 9/1967 Greene 197/17 X 3,422,946 H1969 Rekewitz [97/98 X 3,647,042 3/1972 Smith 197/19 Primary ExaminerRobert E. Pulfrey Assistant Examiner-R. T. Rader Attorney, Agent, or Firm-Ira J. Schaefer [57] ABSTRACT A typewriter is provided with an input and output apparatus having receiving and transmitting bars. The receiving bars are urged by springs and are latched to latches controlled by electromagnet's. A series of decoding levers senses the receiving bars on receiving of input signals for setting one of said decoding levers corresponding to the combination of positions of the receiving bars. A lever rocked by a continuously rotating cam causes the decoding lever so set to be shifted for actuating the type-hammer associated thereto.

11 Claims, 13 Drawing Figures PAIEmmsmmm 31,837,458

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PATENIEUSE IQM SHEET t 0F 7 l l l I I FIGA Pmamanser'w 3,837,258

sum snr 1 FIG. 5 16 CODED INPUT AND OUTPUT APPARATUS FOR TYPEWRITERS CROSS REFERENCE TO RELATED APPLICATION The convention priority application for this invention is Italian Patent Application No. 69435-A/7l filed on July 20, 1971 in Italy.

BACKGROUND OF THE INVENTION:

1. Field of the invention The present invention relates to a coded input and output apparatus for typewriters which is prearranged both to receive in code electric signals corresponding to characters of the keyboard of the machine so as to activate the kinematic striking chain thereof, and to generate electric signals corresponding to the characters printed by the machine.

2. Description of the prior art I Coded input and output apparatus for typewriters having type hammers is known in which the input comprises a plurality of receiving'bars actuated by springs. These bars are retained in a first position by latches controlled by electromagnets and are shifted into a second position by the springs in consequence of the release of these latches when corresponding signals arrive at the electromagnets. The receiving bars are sensed by a series of decoding levers individually associated with the hammers and adapted to be set to a selection position on recognition of a corresponding combination of positions of the receiving bars. Such .known arrangements have the disadvantage of being rather complex and, therefore, bulky and costly.

SUMMARY OF THE INVENTION The object of the present invention is to produce a coded input and output apparatus for typewriters relatively simple, of reduced dimensions and not expensive.

According to the present invention there is provided coded input and output apparatus for typewriters having type hammers, the input means of which comprises a plurality of receiving bars retained by springs and positionable by them by means of the release of corresponding electromagnetically controlled latches on reception of the relative signals, and in which the receiving bars are sensed by a series of decoding levers individually associated with the hammers and adapted to be set to a-selection position on recognition of a corresponding combination of positions of the receiving bars, the apparatus further comprising a cylindrically actuated common element which shifts in a command direction the lever set in this way to 'activatethe hammer associated therewith forstriking, the said common element. being arranged to reset the receiving bars in a subsequent part of its cycle to bring them back under BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention,

the description of one particular embodiment thereof will now be given by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic perspective view of a typewriter in which apparatus embodying the invention is incorporated;

FIG. 2 is a front perspective view of the receiving assembly of the apparatus;

FIG.- 3 is a diagrammatic side view of a number of parts of the assembly of FIG. 2 in the position corresponding to the beginning of a receiving cycle;

FIG. 4 is a diagrammatic side view of the parts shown in FIG. 3 in a stage of the receiving cycle following the foregoing one;

FIG. 5 is a diagrammatic side view of the parts shown in FIGS. 3 and'4 in a further stage of the receiving cycle;

FIG. 6 is a partial plan view of a number of parts of the receiving assembly of FIG. 2 in the position corresponding to the beginningof a receiving cycle;

FIG. 7 is a plan view of the parts shown in FIG. 6 in the position corresponding to the stage of thereceiving cycle shown in FIG. 5;

FIG. 8 is a rear perspective view' of the transmitting assembly of the apparatus;

FIG, 9 is a front perspective view of a number of parts of the transmitting assembly of FIG. 8; 7

FIGS. 10, 11 and 12 show diagrammatically a'number of bars and aslider which form part of the transmit ting assembly, in different relative positions;

FIG. 13 shows diagrammatically the bars of FIGS. 10, 11 and 12 and a-pair of sliders which co-operate with one of these bars, during the simultaneous actuation of two printing keys of the typewriter.

DESCRIPTION OF THE PREFERRED EMBODIMENT The coded input and output apparatus for typewriters is disposed in the lower part of atypewriter 1 (FIG. 1), and comprises in the main two assemblies, these being a receiving assembly 2, and a transmitting assembly 3, the first being disposed somewhat in front of and below the kinematic striking train of the machine and the second below the kinematic train.

The receiving assembly (FIG. 2) comprises a shaft 4 which is caused to rotate clockwise by means of a motor (not shown) and with which a cam 5 is fast. This cam has'three lobes (FIGS.'2 and .3) and'is arranged to co-operate with a cam follower roller 7 of a rocking lever 8, which can oscillate about a fixed spindle 9. On the shaft 4 there is also fixed adisc-l0 equipped with threemagnetic plates 10, which induce a signal in a detector 11 known per se as they. pass by. An arm 12 of the rocking lever B is provided with a cam follower roller :13 arranged to co-operate with a cam 14 fast with a shaft 15 which can turn in the frame of the machine and to which a lug plate l6-is fixed. 1

The cam follower roller'7 of therocking lever 8 is kept permanently in contact with the active profile of the cam 5 by a coilspring 17, while another coil spring 18 fixed to a plate 19 fast with the shaft 15 tends to cause this shaft, and therefore also the lug plate 16, to rotate clockwise in FIGS.'2 and 3. The arm 12 is moreover connected by means of a connecting rod 20 to the core of a solenoid 21. The lug plate 16, which is substantially U-shaped, has a projecting edge 23 and a C shapedbent portion 24 parallel to the shaft 15. Located on the C-shaped bent portion throughout its length is a spiral spring 29 fixed at the ends of the bent portion 24 On a plate 25 (FIG. 2) fast with the frame of the machine there are mounted a stack of receiving bars 26 (six in the case of the embodiment illustrated), each of which is provided with a plurality of notches 27. Slotted holes 28 (FIGS. 6 and 7) formed at the ends of the bars fit over corresponding pins 31 fast with the plate 25, thus allowing lengthwise shifting of the bars with respect to the plate 25. Each bar 26 is pulled to the left in FIGS. 2, 6 and 7 by a corresponding coil spring 32 the ends of which are fixed to projections 33 and 34 (FIGS. 6 and 7), respectively of the bar and of a bell crank lever 35 pivoting on a pin 36 carried by the plate 25. This lever has a lug 37 designed to engage with a corresponding tooth 38 of the bar 26, which tooth is provided with an inclined back edge 39. The relative position of the projections 33, 34 and of the pin 36 is such as to compel the spring 32 to bear on the pin 36 in such manner as to produce two lengths of spring which are substantially rectilinear and form a certain angle between them, as is clearly visible in FIGS. 6 and 7. With this structural arrangement, the spring 32 is able to generate forces of two different directions, one for shifting the bar 26 and the other for rotating the lever 35. To a fork 41 of one of the arms of the bell crank lever 35 there is connected an armature 42 of a corresponding solenoid 43 also fixed to the plate 25. The levers 35 and teeth 38 thereby act as electromagnetically controlled latches.

The receiving bars 26 can be shifted to the right in FIGS. 2, 6 and 7, overcoming the elastic reaction of the springs 32, by means of a recocking bail 44 pivoting on a pin 45 fixed to the plate 25. This bail is provided with lug 46 arranged to co-operate with one end of the bars themselves, and also with another lug 47 arranged to co-operate with a roller 48 pivoted on the rocking lever 8 at an intermediate point between its axis of rotation and the cam follower roller 13. Suitably, a stop pin 50 fixed to the plate 25 limits the angular excursion, clockwise in FIGS. 6 and 7, of the bail 44. In front of the receiving bars 26 there are disposed decoding levers 51 (FIGS. 2 and 3) the number of which is equal to that of the type hammers 52 (FIG. 2) with which the machine is equipped. Each lever 51 is articulated by a pin 53 (FIGS. 2 and 3) to a corresponding actuating lever 54 pivoted on a spindle 55, is guided by a slot 56 (FIG. 2) in the plate 25 and is normally kept rotated towards the receiving bars 26 by a coil spring 57. Each lever is moreover provided with a hook 58 and with a bearing surface 59 designed to co-operate with the projecting edge 23 and with the spring 29 of the lug plate 16, respectively.

Each actuating lever 54 is arranged to activate, in the manner which will be described hereinafter, the kinematic striking train of the machine to bring the corresponding type hammer 52 (FIG. 2) against the printing cylinder or platen of the machine. This kinematic striking train, which is known per se, comprises a printing lever 60 (FIGS. 2 and 3) pivoting on a spindle 61 and pulled by a coil spring 62. The upper end 63 of this lever is connected by means of tie rods 64 (FIG. 2) and a bell crank lever 65 to one end of the corresponding type hammer 52. To the printing lever 60 (FIGS. 2 and 3) there are pivoted, by means of pins 67 and 68, a catch 71 and a lever 72, respectively, which are elastically connected by means of a coil spring 73 the ends of which are fixed to corresponding projections of the first and the second of these parts. The lever 72 which, in the inoperative position of the apparatus is engaged with the catch 71, as shown in FIGS. 2 and 3, is provided with a projection 74 designed to co-operate with a command lug plate 75 which is caused to rotate cyclically in manner known per se.

The catch 71 has a lug 76 (FIG. 2) designed to cooperate with a plate 77 shifted by a lever 78 actuated, in turn, by the corresponding printing key (not shown) in manner known per se. The same lug 76 co-operates with a projection 79 (FIG. 3) formed on the end of the actuating lever 54 to activate, in the manner which will be described hereinafter, the corresponding printing lever 60.

The transmitting assembly of the apparatus, which can be seen in front in FIG. 9 and at the rear and partially in FIG. 8, comprises a plurality of sliders 81 (FIGS. 3, 9 and 8) slidable vertically in a support 82. Each slider is provided with a vertical arm 83 (FIGS. 9 and 3) and a projection 84, the first guided in a slit 85 and the second in a slotted hole 86 in the support itself. On each slider 81 there is formed an edge 87 of V-shaped section (FIGS. 3, 9 and 10) and each arm 83 bears a fork 88 (FIGS. 3 and 9) designed to co-operate with a corresponding lug 91 (FIGS. 3 and 2) of the corresponding printing lever 60. Coil springs 92 (FIGS. 9 and 3), the ends of which are fixed to the projections 84 of the sliders 81 and to corresponding projections 93 of the support 82, tend to shift the sliders upwardly. The width of the forks 88 is greater than the thickness of the lugs 91, as a result of which, in the inoperative position of the printing levers 60 and of the sliders 81 (FIG. 3), each lug 91 bears on the lower prong of each fork 88, leaving a certain play with respect to the other prong. The force exerted by the spring 62 (FIGS. 3 and 2) of each printing lever 60 is greater than that exerted by the spring 92 (FIG. 3) of the corresponding slider 81, as a result of which, in the inoperative position of the apparatus, these levers keep the sliders lowered, as shown in FIGS. 9 and 3.

The support 82 bears six transmitting bars 94 (FIGS. 9, 3 and 8), each of which can slide in the support 82, being supported by pins 95 (FIG. 8) fast with the support itself and coupled to corresponding slotted holes 96 in the bars. Each bar is provided with a plurality of inclined surfaces 97, 98 (FIGS. 9 and 10) designed to co-operate with the V-shaped edge 87 of the sliders 81; as can be seen in FIG. 10, the inclined surfaces 97 and 98 have opposite inclinations and are followed by slots 97a. Each bar 94 is provided with a slot 99 (FIG. 9) with the inside of which there co-operates a lug 100 of a bail 101 (FIG. 8) pivoting on a pin 102 fixed to the support 82. The cross-piece 103 of each bail is designed to open and close a reed relay magnetic switch, comprising a permanent magnet 104 and a pair of metal contacts 105, between which this cross-piece can dispose itself to form a screen for the magnetic flux between the magnet and the aforesaid contacts. These switches, which are shown per se, are closed when the cross-piece 103 is not located between the magnet 104 and the contacts 105 and are open when the crosspiece is located between these parts, for the bars 94 ghifted to the left and to the right, respectively, in FIG.

On each bail 101 there moreover acts a coil spring 106 fixed to projections 107 and 108, which balances the action of the magnet 104 on the bail itself.

Another bar 111 for commanding reading (FIGS. 9 and is also mounted slidably on the pins 95 (FIG. 8) of the support 82 and has a series of inclined surfaces 112 (FIGS. 9 and 10) which are located a little higher with respect to the inclined surfaces 97, 98 of the bars 94 and which are inclined like the surfaces 98. The bar 111 is also provided with a slot 113 (FIG. 9) co-operating with a lug 114 of a bail 115 (FIGS. 8 and 9) pivoting on a pin 116; an arm of this bail is provided with a lug 117 designed to activate a microswitch 118 carried by the support 82. A coil spring 119 normally keeps the bail 115 turned anticlockwise in FIG. 8 and the bar 111 shifted to the left.

A positioning bail 121 (FIG. 9) which can turn on a pin 122 fixed to the support 82 is normally kept turned anticlockwise by-a spring 123 and is provided with a pin 124 designed to co-operate with the inside of one of the two notches 125 formed in the bars 94.

The solenoids 43 (FIG. 2) of the receiving assembly 2 and the contacts 105 (FIG. 8) of the transmitting assembly 3 are connected to an electric circuit (not shown) by means of which it is possible to transmit and receive electric signals corresponding to the characters of thekeyboard of the typewriter in which the apparatus embodying the invention is incorporated.

The operation of this apparatus takes place in, the following manner. Consider initially the case in which there takes place the reception of a message in code through electric signals sent to the solenoids 43 (FIG. 2) of the receiving assembly of FIG. 2.

During this reception, the electromagnet 21 (FIG. 3) is de-energized and, therefore, the rocking lever 8, controlled by the cam 5, oscillates continuously. Each receiving cycle begins through the agency of the detector 11 when the cam S is located in a position such as to have the cam follower roller 7 of the rocking lever 8 in correspondence with the upper end of one of its lobes 6, as shown in FIGS. 2 and 3. In this state, the aforesaid electric signals energize one or more solenoids 43, thereby causing the respective armatures 42 (FIG. 7) to be shifted in the direction of the arrow shown in FIG. 7, producing the clockwise rotation of the levers 35 and overcoming the elastic reaction of the respective coil springs 32. Therefore, the lugs 37 of these levers which, as shown in FIG. 6, locked the teeth 38 of the receiving bars 26 before the energization, release these teeth, allowing one or more of the bars to shift to the left, as shown in FIG. 7. At the end of this movement, notches 27 of the bars 26 are in front of the decoding lever 51 (FIG. 2) corresponding to the character selected.

The rotation of the cam 5 being continued (FIG; 4), the anticlockwise rotation of the rocking lever 8 is permitted, as shown in FIG. 4 and, because of the raising of the roller 13 with respect to the cam 14, clockwise rotation of the command .lug plate 16, controlled by the spring l8, occurs. The bent portion 24 of the lug plate 16 moves to the left in FIG. 4, allowing anticlockwise rotation of all the decoding levers 51, which bear on the bars 26 under the control of the springs 57. Only the selected decoding lever,'encountering in front of it an assembly of substantially aligned notches, can enter the notches, as is assumed is happening in the case of the lever 51 shownin FIG. 4.

The rotation of the cam 5 being still continued (FIG. 5), there are corresponding rotations of the rocking lever 8 and of the lug plate 16, during which there occurs, first, the detachment of the angle 24 of the latter from the bearing surface 59 of the selected decoding lever and, thereafter, the engagement of the projecting edge 23 of the lug plate with the hook 58 of the lever. In the final part of the rotation of the lug plate 16, the edge 23 pulls the selected lever 51 down in' FIG. 5, causing the clockwise rotation of the corresponding actuating lever 54. To this rotation there corresponds, through the coupling of the projection 79 of this lever with the lug 76 of the catch 71, a rotation of this catch which is entirely similar to that impressed on the catch by the plate 77 (FIG. 2) in consequence of the actuation of the lever 78 obtained by depressing the cone sponding printing or typing key of the machine.

In this way there is activated the kinematic printing train of the machine, which operates in the following manner. The turning of the catch 71 (FIGS. 4 and 5) disengages the catch from the lever 72 and the rotation of the lever 72 under the action of the spring 73. At the same time, known means (not shown) cause the lug plate 75 to turn clockwise and, when the projecting part 74 of the lever 72 is disposed in the path of thelug plate, this lever is pulled to the right in FIG. 5 by this lug plate, producing the rotation of the printing lever 60 about the spindle 61 to bring it from the position of FIG. 4 to that of FIG. 5. In consequence, the end 63 of this lever effects, through the tie rods 64 (FIG. 2) and the lever 65, the rotation of the corresponding type hammer 52.

During the following rotation of the cam 5 (FIG. 5), in order to assume again the position with respect to the rocking lever 8 which it had in FIG. 3, there is a clockwise rotation of the rocking lever, during which the lug plate 16 is caused to turn anticlockwise, reloading the spring 18 of the lug plate to store therein sufficient energy for effecting another cycle. During this last rotation, the spring 29 strikes against the surfaces 59 of the levers 55, absorbing the impact energy, and therefore causes the levers 51 to rotate anticlockwise, bringing them back into their respective initial positions with the minimum noise. The selected actuating lever 54 is brought back into the initial position by the corresponding catch 71 of the printing lever 60 during resumption of the original conditions of the kinematic striking chain, which takes place in manner known per se.

During the rotation of the cam 6 to bring itself from the position of FIG. 5 to that of FIG. 3, there also takes place the recocking of the receiving bars 26, which is effected by the action of the bail 44 (FIGS. 2, 6 and 7). In fact, during the aforesaid rotation, the roller 48 of the rocking lever 8 co-operates with the lug 47 of this bail, causing the rotation thereof anticlockwise in FIG.

7.' The lug 46 of the bail 44 therefore shifts the selected bars 26 to the right from the position of FIG. 7 to that of FIG. 6. During this-shifting action, the lugs 37 of the levers 35, co-operating with the inclined back edges 39 of the teeth 38, are cammedover the teeth and engage the teeth again as in FIG. 6. v

In the receiving assembly of the apparatus, the relative position of the axis of rotation of the rocking lever 8 (FIG. 3), of the axis of the roller 13 and of the axis of the shaft 15 of the lug plate 16 and also the form of the cam 14 are such as to cause the rotation of the lug plate 16 to pass from the configuration of FIG. 3 to that of FIG. to take place at a speed which is initially very low and increasing during the cycle until the maximum is reached at the end of the cycle. In fact, to pass from the configuration of FIG. 3 to that of FIG. 4, to a predetermined rotation of the rocking lever 8, there corresponds a small rotation of the lug plate 16, while to pass from the configuration of FIG. 4 to that of FIG. 5, to the same rotation of the rocking lever there corresponds a rotation of the lug plate 16 much greater than the preceding one. This is due to the fact that the path of the roller 13, around the configuration of FIG. 3, is substantially tangent to the profile of the cam 14, while during the last part of the rotation of the rocking lever 8 around the position of FIG. 5 this path is substantially perpendicular to the aforesaid profile.

It is therefore obvious that in the constructional arrangement described the cyclically actuated common element 8 shifts downwardly the lever 51 set by the bars 26 to activate the hammer 52 associated therewith for striking. The common element 8 recocks the receiving bars 26 to bring them back under the control of the electromagnets 43.

The operation of the transmitting assembly of the apparatus takes place in the following manner. When a key of the keyboard of the machine is depressed, the corresponding lever 78 (FIG. 2) is caused to rotate and the plate 77 is raised and shifts the lug 76 of the catch 71, causing the catch to rotate to give rise to a printing cycle, which takes place under the conditions described before. The selected printing lever 60 is therefore caused to rotate from the position of FIG. 4 to that of FIG. 5, to which there corresponds the raising of its lug 91. The spring 93 then pulls the slider 81 upwardly, bringing the edge 87 up to the bars 94 (FIG. 10, stroke a). The edge 87 can now be located in correspondance with the inclined surfaces 97 or 98, in correspondence with the slots 970. In the first case, the selected slider 81 co-operating with the surface 97 shifts to the left the bar 94 previously positioned to the right, or sliding on the surface 98 shifts to the right the bars 94 previously positioned to the left. In the second case, the slider 81 makes an idle stroke and leaves the bar 94 in the previous position.

The shifting of the bars 94, through the medium of the springs 92, takes place more slowly than the shifting of the lug 91, so that the lower prong of the fork 88 leaves the corresponding lug 91. The positioning of the bars 94 therefore does not exert any effect on the printing lever 60 and; therefore on the striking of the selected hammer. Almost at the end of its stroke, the slider 81 inserts itself in the slots 97a (FIG. 12), which are in correspondence with the ends of inclined surfaces 97 and 98.

During this last part of the shifting of the slider, the V-shaped edge 87 also co-operates with an inclined surface 112 (FIG. 12) of the reading command bar 111, causing it to shift to the right in FIG. 12. During the shifting of the bars 94, the pin 124 is cammed out of one notch 125 into the other in opposition to the action of the spring 123. The positioning bail 121, exerting a constant load, thus assists in reducing the range of variation between the resistant forces on the spring 92 when a single bar is shifted and the resistant forces corresponding to the shifting of six bars. After the shifting of the bars 94, the position bail 121, introducing itself into one of the notches 125, moreover corrects the final position of the said bars.

Therefore, during the first part of the shifting of the selected slider 81, there may be shiftings of one or more bars 26 to which there correspond rotations of the corresponding bails 101 controlled by the slots 99 (FIG. 9) coupled with the lugs 100 of the bails themselves. In this way, there is achieved a desired combination of openings and closings of switches (each constituted by an assembly consisting of contacts 105, a magnet 104 and a cross-piece 103) which is dependent on the angular trim or position of the bails 101. The assembly of these switches is therefore designed to send a complex of signals corresponding to the character selected to the aforesaid electric circuit of the transmitting assembly (not shown). These signals are sent to this circuit when the closing of the switch 118 (FIG. 8) commanded by the bar 111 (FIG. 9) takes place. In fact this bar, as has been said, shifts to the right in FIGS. 9 and 12 during the last part of the shifting of the selected slider 81, thus causing, through the coupling between the slot 113 (FIG. 9) and the lug 114, the rotation of the bail 115, the lug 117 of which closes the switch 118.

The assembly of bars 94 is also arranged to prevent the sending of the aforesaid signals to the electric circuit of the transmitting assembly when two printing keys are actuated at the same time. If two keys are depressed simultaneously, the respective sliders 81 (FIG. 13) are brought simultaneously towards the bars 94 and each of these sliders, co-operating with the inclined surfaces 97, 98 of these bars, tends to cause a predetermined series of bars 94 to shift to the left or right. Since there is at least one bar among the bars 94 of the two aforesaid series which, according to one code, must be shifted to the right, and, according to theother code, must be shifted to the left, this bar presents a surface 97 and a surface 98 simultaneously to the two selected sliders 81, as a result of which the sliders are locked and do not succeed in coming into contact with the inclined surfaces 112 of the reading command bar 111. FIG. 13 shows a bar 94a belonging to one of the two aforesaid series which presents the inclined surfaces 97 and'98 of opposite inclinations to the two selected sliders 81.

When each printing lever 60 returns to its inoperative position shown in FIGS. 2 and 3, the corresponding slider 81 is brought back into the position shown in FIGS. 3 and 10, with the edge 87 at the distance a (FIG. 10) from the bars 94. These bars remain in the position in which they are at the end of a cycle, owing to the action of the pin 124 (FIG. 9) of the positioning bail 121, until the moment when they are repositioned during a following cycle. On the other hand, the reading command bar 111 is brought back, at the end of each cycle, to the position in which it was at the beginning of the cycle by the spring 119 of the bail 115.

During manual operation of the machine, the electromagnet 21 can be energized. In this case, the roller 7 (FIG. 3) leaves the cam 6 and the rocking lever 8 remains locked, avoiding useless movement of the levers 51 and the bars 26.

We claim:

1. In a coded input and output apparatus for typewriters having type hammers, including a plurality of receiving notched bars and a plurality of transmitting bars, a plurality of springs pulling said receiving bars,

latch means latching said receiving bars against the action of said springs, electromagnetic means responsive to corresponding input signals for selectively releasing said latch means for causing said springs to position said receiving bars for aligning corresponding notches thereof according to a character being selected, decoding levers disposed beneath said receiving bars and individually engageable with said hammers for the selective striking thereof, releasing means for causing said decoding levers to sense said receiving bars, so that one of said decoding levers enters into the corresponding notches of said receiving bars, and relatching bail means for relatching said receiving bars to said latch means, wherein the improvement comprises:

a. power driven cam means; b. cam follower means for cyclically following said cam means; c. said releasing means comprising a first portion that is movable to allow said one decoding lever to enter said corresponding notches and also includ-' ing a common bail;

d. said common bail being operated by said cam follower means and moving from a rest position to an actuated position against an end of said entered one of said decoding levers to translate linearly said one decoding lever for actuating the associated one of said hammers for striking; and

e. an intermediate member operatively connecting said cam follower means with said relatching bail means for returning said receiving bars to their latched position.

2. Apparatus according to claim 1, wherein said cam follower means comprise a rocking lever cooperating with said cam means, said rocking lever including a cam follower portion and the apparatus further comprising a cam member fixed to said common bail and a tensioning spring pulling said common bail for holding said cam member in contact with said cam follower portion of said rocking lever for causing said entered one of said decoding levers to be yieldingly actuated through said common bail by said tensioning spring.

3. Apparatus according to claim 1, wherein said cam means include a cam continuously rotatable and said cam follower means include a rocking lever which is caused to oscillate by said cam continuously rotatable, and further comprising another electromagnetic means said other electromagnet on receiving of a corresponding starting signal operating said rocking lever from a rest position away from said continuously rotatable cam to an operative position following said rotatable cam.

4. Apparatus according to claim 1, wherein said decoding levers include a corresponding hook and are urged by corresponding springs, said common bail including a lug plate provided with aprojecting part adapted to engage said corresponding hook of said decoding levers, when entered on the aligned notches, said first portion of said releasing means including a second'part of said lug plate for normally keeping said decoding levers away from said notched receiving bars against the action of the springs corresponding to said decoding levers.

5. Apparatus according to claim 1, wherein said cam follower means include a reciprocal moving member supporting a corresponding roller, said relatching bail means including a bail cooperating with said receiving bars, and said intermediate member includes a projecting lug of said relatching bail, said lug contacting said corresponding roller for relatching said receiving bars during the reciprocal movement of said reciprocal moving member.

6. Apparatus according to claim 1, further comprismg:

said plurality of transmitting bars for emitting output coded signals;

encoding levers for positioning said transmitting bars in correspondence to a character being printed; and

intermediate printing levers individually connected with said hammers and responsive to the operation of said decoding levers for actuating the connected one of said hammers for striking, each one of said printing levers cooperating with said decoding levers for positioning said transmitting bars in correspondence of the striking of the selected hammer corresponding to said character.

7. In a coded input and output apparatus having type hammers, intermediate printing levers, and means selectively operating said printing levers for causing the striking of one selected of said hammers, comprising a plurality 'of transmitting bars permutatively shiftable to emit coded signals corresponding to said selected one of said hammers, said transmitting bars being provided with a series of inclined edges, and a series of encoding elements each including an end with plural abutments, said encoding elements adapted to co-operate with said inclined edges for positioning said transmitting bars, wherein the improvement comprises:

a. spring means urging said encoding element for shifting said encoding elements from a rest to an operative position causing said encoding elements to cooperate with said inclined edges for positioning said bars, and

b. holding elements each one carried by one corresponding of said printing levers and normally contacting the corresponding encoding elements against one of said plural abutments so as to keep said encoding levers in said rest position against the action of said spring means, said means operating said intermediate printing levers causing said holding elements to release said encoding levers from the action of said spring means and said holding elements moving from said oneiof said plural abutments to another abutment for the shifting of said plurality of transmitting bars under the action of said spring means and said holding elements.

8. Apparatus according to claim 7, wherein said hold-. ing elements include aligned lugs, and said transmitting bars include a series of sliders stacked in vertical planes and including lowerand upper lengthened edges extending horizontally,,said sliders being slidable in horizontal supports disposed adjacent below said aligned lugs, said inclined edges being formed in said lower edges of said transmitting sliders and said encoding elements including vertical sliders shiftable upwardly by the action of said spring means, as a result of which the vertical component of the force of said encoding element on said inclined edges over said horizontal supports is balanced by the weight of said transmitting bars.

9. Apparatus according to claim 7, further comprising magnetically controlled switches associated to said transmitting bars, each of said switches including magnet means for generating a magnetic flux, contact switches, and balancing spring means operating on said' screen element for counterbalancing the attractive force of said magnet means on said screen element.

10. Apparatus according to claim 7, wherein said transmission bars are also provided with positioning notches, further comprising a spring loaded positioning element adapted to cooperate with said positioning notches for correcting the positions of said plurality of transmitting bars and adding a further constant load which reduces the variation of load on said encoding elements, arising in shifting one or more of said transmitting sliders.

11. In a code input and output apparatus for typewriters having type hammers, intermediate printing levers associated with said hammers, and means selectively actuating said printing levers for causing the striking of one selected of said hammers, comprising a plurality of receiving bars having notches; spring means pulling said receiving bars; latch means for selectively releasing said receiving bars, so as to cause said springs to position said receiving bars for aligning corresponding notches thereof according to a character being selected; a series of decoding levers individually associated with said hammers and adapted to singularly enter on the aligned notches, transmitting bars adapted to emit coded output signals in correspondence to said character being selected, said transmitting bars being provided with a series of inclined edges; and a series of encoding elements associated with said hammers and adapted to cooperate with said edges for positioning said bars according to a combination of positions corresponding to a striking hammer, wherein the improvement comprises:

a. a power actuated common element, said common element actuates a common bail which is movable against the one entered of said decoding levers for linearly shifting said one entered of said decoding levers so as to activate the associated one of said type hammers for striking;

b. restoring means for said receiving bars operatively connected with said common element by an intermediate member for resetting said receiving bars under the control of said latch means;

c. spring means urging said encoding element toward an operative position for positioning said transmitting bars, and

d. holding elements fixed to said intermediate printing levers for normally holding at rest said encoding elements against the action of said spring means, and releasing the individually connected of said encoding elements upon actuation of said corresponding printing level so as to cause said spring means to position said transmitting bars after said printing lever has actuated said holding element. 

1. In a coded input and output apparatus for typewriters having type hammers, including a plurality of receiving notched bars and a plurality of transmitting bars, a plurality of springs pulling said receiving bars, latch means latching said receiving bars against the action of said springs, electromagnetic means responsive to corresponding input signals for selectively releasing said latch means for causing said springs to position said receiving bars for aligning corresponding notches thereof according to a character being selected, decoding levers disposed beneath said receiving bars and individually engageable with said hammers for the selective striking thereof, releasing means for causing said decoding levers to sense said receiving bars, so that one of said decoding levers enters into the corresponding notches of said receiving bars, and relatching bail means for relatching said receiving bars to said latch means, wherein the improvement comprises: a. power driven cam means; b. cam follower means for cyclically following said cam means; c. said releasing means comprising a first portion that is movable to allow said one decoding lever to enter said corresponding notches and also including a common bail; d. said common bail being operated by said cam follower means and moving from a rest position to an actuated position against an end of said entered one of said decoding levers to translate linearly said one decoding lever for actuating the associated one of said hammers for striking; and e. an intermediate member operatively connecting said cam follower means with said relatching bail means for returning said receiving bars to their latched position.
 2. Apparatus according to claim 1, wherein said cam follower means comprise a rocking lever cooperating with said cam means, said rocking lever including a cam follower portion and the apparatus further comprising a cam member fixed to said common bail and a tensioning spring pulling said common bail for holding said cam member in contact with said cam follower portion of said rocking lever for causing said entered one of said decoding levers to be yieldingly actuated through said common bail by said tensioning spring.
 3. Apparatus according to claim 1, wherein said cam means include a cam continuously rotatable and said cam follower means include a rocking lever which is caused to oscillate by said cam continuously rotatable, and further comprising another electromagnetic means said other electromagnet on receiving of a corresponding starting signal operating said rocking lever from a rest position away from said continuously rotatable cam to an operative position following said rotatable cam.
 4. Apparatus according to claim 1, wherein said decoding levers include a corresponding hook and are urged by corresponding springs, said common bail including a lug plate provided with a projecting part adapted to engage said corresponding hook of said decoding levers, when entered on the aligned notches, said first portion of said releasing means including a second part of said lug plate for normally keeping said decoding levers away from said notched receiving bars against the action of the springs corresponding to said decoding levers.
 5. Apparatus according to claim 1, wherein said cam follower means include a reciprocal moving membEr supporting a corresponding roller, said relatching bail means including a bail cooperating with said receiving bars, and said intermediate member includes a projecting lug of said relatching bail, said lug contacting said corresponding roller for relatching said receiving bars during the reciprocal movement of said reciprocal moving member.
 6. Apparatus according to claim 1, further comprising: said plurality of transmitting bars for emitting output coded signals; encoding levers for positioning said transmitting bars in correspondence to a character being printed; and intermediate printing levers individually connected with said hammers and responsive to the operation of said decoding levers for actuating the connected one of said hammers for striking, each one of said printing levers cooperating with said decoding levers for positioning said transmitting bars in correspondence of the striking of the selected hammer corresponding to said character.
 7. In a coded input and output apparatus having type hammers, intermediate printing levers, and means selectively operating said printing levers for causing the striking of one selected of said hammers, comprising a plurality of transmitting bars permutatively shiftable to emit coded signals corresponding to said selected one of said hammers, said transmitting bars being provided with a series of inclined edges, and a series of encoding elements each including an end with plural abutments, said encoding elements adapted to co-operate with said inclined edges for positioning said transmitting bars, wherein the improvement comprises: a. spring means urging said encoding element for shifting said encoding elements from a rest to an operative position causing said encoding elements to cooperate with said inclined edges for positioning said bars, and b. holding elements each one carried by one corresponding of said printing levers and normally contacting the corresponding encoding elements against one of said plural abutments so as to keep said encoding levers in said rest position against the action of said spring means, said means operating said intermediate printing levers causing said holding elements to release said encoding levers from the action of said spring means and said holding elements moving from said one of said plural abutments to another abutment for the shifting of said plurality of transmitting bars under the action of said spring means and said holding elements.
 8. Apparatus according to claim 7, wherein said holding elements include aligned lugs and said transmitting bars include a series of sliders stacked in vertical planes and including lower and upper lengthened edges extending horizontally, said sliders being slidable in horizontal supports disposed adjacent below said aligned lugs, said inclined edges being formed in said lower edges of said transmitting sliders and said encoding elements including vertical sliders shiftable upwardly by the action of said spring means, as a result of which the vertical component of the force of said encoding element on said inclined edges over said horizontal supports is balanced by the weight of said transmitting bars.
 9. Apparatus according to claim 7, further comprising magnetically controlled switches associated to said transmitting bars, each of said switches including magnet means for generating a magnetic flux, contact means actuatable by said magnetic flux and a screen element disposable between said magnet means and said contact means, said screen means being operatively connected with one associated of said transmitting bars for screening the flux of the corresponding magnet for actuating selectively the associated of said switches, and balancing spring means operating on said screen element for counterbalancing the attractive force of said magnet means on said screen element.
 10. Apparatus according to claim 7, wherein said transmission bars are also provided with positioning notches, further comprising a spring loaded poSitioning element adapted to cooperate with said positioning notches for correcting the positions of said plurality of transmitting bars and adding a further constant load which reduces the variation of load on said encoding elements, arising in shifting one or more of said transmitting sliders.
 11. In a code input and output apparatus for typewriters having type hammers, intermediate printing levers associated with said hammers, and means selectively actuating said printing levers for causing the striking of one selected of said hammers, comprising a plurality of receiving bars having notches; spring means pulling said receiving bars; latch means for selectively releasing said receiving bars, so as to cause said springs to position said receiving bars for aligning corresponding notches thereof according to a character being selected; a series of decoding levers individually associated with said hammers and adapted to singularly enter on the aligned notches, transmitting bars adapted to emit coded output signals in correspondence to said character being selected, said transmitting bars being provided with a series of inclined edges; and a series of encoding elements associated with said hammers and adapted to cooperate with said edges for positioning said bars according to a combination of positions corresponding to a striking hammer, wherein the improvement comprises: a. a power actuated common element, said common element actuates a common bail which is movable against the one entered of said decoding levers for linearly shifting said one entered of said decoding levers so as to activate the associated one of said type hammers for striking; b. restoring means for said receiving bars operatively connected with said common element by an intermediate member for resetting said receiving bars under the control of said latch means; c. spring means urging said encoding element toward an operative position for positioning said transmitting bars, and d. holding elements fixed to said intermediate printing levers for normally holding at rest said encoding elements against the action of said spring means, and releasing the individually connected of said encoding elements upon actuation of said corresponding printing level so as to cause said spring means to position said transmitting bars after said printing lever has actuated said holding element. 